Systems and methods for treatment of sleep apnea

ABSTRACT

A system for revisably treating an airway disorder is provided with an implant body configured to conform to an airway-interface tissue site in a manner compatible with normal physiological function of the site. In some embodiments, first and second openings extend through first and second implant ends, respectively, for permitting a tissue plug to grow through each opening. Methods of using and revising such systems are also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.13/053,025, filed Mar. 21, 2011, now U.S. Pat. No. 8,776,799, whichclaims priority to: U.S. Provisional Application No. 61/315,835, filedMar. 19, 2010; U.S. Provisional Application No. 61/315,838, filed Mar.19, 2010; U.S. Provisional Application No. 61/347,348, filed May 21,2010; U.S. Provisional Application No. 61/347,356, filed May 21, 2010;U.S. Provisional Application No. 61/367,707, filed Jul. 26, 2010; U.S.Provisional Application No. 61/418,238, filed Nov. 30, 2010; U.S.Provisional Application No. 61/419,690, filed Dec. 3, 2010, each ofwhich is herein incorporated by reference in its entirety.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

FIELD

The invention relates to the field of methods and devices for thetreatment of obstructive sleep apnea, and more particularly to openingthe airway of subjects with symptoms of obstructive sleep apnea.

BACKGROUND

Sleep apnea is defined as the cessation of breathing for ten seconds orlonger during sleep. During normal sleep, the throat muscles relax andthe airway narrows. During the sleep of a subject with obstructive sleepapnea (OSA), the upper airway narrows significantly more than normal,and during an apneic event, undergoes a complete collapse that stopsairflow. In response to a lack of airflow, the subject is awakened atleast to a degree sufficient to reinitiate breathing. Apneic events andthe associated arousals can occur up to hundreds of times per night, andbecome highly disruptive of sleep. Obstructive sleep apnea is commonlybut not exclusively associated with a heavy body type, a consequence ofwhich is a narrowed oropharyngeal airway.

Cyclic oxygen desaturation and fragmented sleeping patterns lead todaytime sleepiness, the hallmark symptom of the disorder. Furtherconsequences of sleep apnea may include chronic headaches anddepression, as well as diminished facilities such as vigilance,concentration, memory, executive function, and physical dexterity.Ultimately, sleep apnea is highly correlated with increased mortalityand life threatening co morbidities. Cardiology complications includehypertension, congestive heart failure, coronary artery disease, cardiacarrhythmias, and atrial fibrillation. OSA is a highly prevalent diseasecondition in the United States. An estimated 18 million Americans sufferfrom OSA to degrees that range from mild to severe, many of whom areundiagnosed, at least in part because the afflicted subjects are oftenunaware of their own condition.

Treatment of OSA usually begins with suggested lifestyle changes,including weight loss and attention to sleeping habits (such as sleepposition and pillow position), or the use of oral appliances that can beworn at night, and help position the tongue away from the back of theairway. More aggressive physical interventions include the use ofbreathing assist systems that provide a positive pressure to the airwaythrough a mask that the subject wears, and which is connected to abreathing machine. In some cases, pharmaceutical interventions can behelpful, but they generally are directed toward countering daytimesleepiness, and do not address the root cause. Some surgicalinterventions are available, such as nasal surgeries, tonsillectomyand/or adenoidectomy, reductions in the soft palate, uvula or the tonguebase, or advancing the tongue base by an attachment to the mandible andpulling the base forward. These surgical approaches can be quiteinvasive and thus have a last-resort aspect to them, and further, simplydo not reliably alleviate or cure the condition. There is a need forless invasive procedures that show promise for greater therapeuticreliability. There is additional need for the ability to reverseprocedures or otherwise revise the procedure, thus allowing for theability to reverse or otherwise revise the effects of the procedure dueto side effects or other undesirable outcomes which may result from theprocedure. Additionally, there is the need to do these proceduralreversals or revisions in a manner that does not require excessivetissue cutting or invasiveness which can act as a deterrent for patientsor physicians to perform such a revision procedure.

SUMMARY OF THE DISCLOSURE

The invention relates to a method of alleviating obstructive collapse ofairway-forming tissues, and for devices with which to implement themethod. Typical patients for whom the method and device may providetherapeutic benefit are those who suffer from obstructive sleep apnea.The method includes implanting a device at a site in the tissue andbioeroding the bioerodible portion of the device to change the shape ofthe device and to remodel the airway-forming tissue. The implanteddevice is sized and shaped to conform to the airway-forming tissue sitein a manner compatible with normal physiological function of the site;and includes a resiliently deformable portion and a bioerodible portion.In, typical embodiments of the method, remodeling the airway-formingtissue results in the airway being unobstructed during sleep, andfurther, typically, the thus-unobstructed airway diminishes thefrequency of apneic events. Remodeling may include reshaping orotherwise altering the position or conformation of airway associatedtissue so that its tendency to collapse during sleep is diminished.

The airway is formed from various tissues along its length from themouth to the lungs. Embodiments of the method include implanting aflexible implant, such as an elastomeric device, into any one or more ofthese tissues, including, for example, the soft palate, the tongue,generally the base of the tongue, and the pharyngeal walls, typicallythe posterior and lateral portions of the pharyngeal wall.

In some embodiments, the device is in a deformed shape when implanted,and a bioerodable portion erodes to thereby release a tensioned shape ofthe implant to apply retraction forces to the site.

With regard to the bioeroding of the bioerodible portion of the device,this may occur over a time span that ranges from days to months. In someembodiments, the bioeroding proceeds at a rate that correlates with theratio of the biologically-exposed surface area of the bioerodibleportion to the volume of the bioerodible portion.

In some embodiments of the method, the bioerosion occurs at a rate thatis sufficiently slow for the tissue site to recover from the implantingprior to the device substantially changing shape. In some of theseembodiments, the recovery of the tissue site includes a forming offibrotic tissue around the device, which typically stabilizes the devicein the site, and provides the device greater leverage with which toreform the shape of the implant site and its surrounding tissue. In someembodiments, after implanting, and as part of the healing response orrecovery from the implantation wound, the newly formed fibrotic tissuesinfiltrates into holes, pores, or interstices in the device. In someembodiments of the method, a bioactive agent, previously incorporatedinto the bioerodible material, is released or eluted from thebioerodible portion of the device as it is eroding.

In another aspect of the methods described herein, a method of forming adevice to alleviate obstructive collapse of an airway during sleep isprovided. The method includes forming a resiliently deformable materialinto an initial shape that corresponds to the preferred shape of thedevice, the initial shape having a site for accommodating bioerodiblematerial; changing the initial shape of the resiliently deformablematerial into a non-preferred shape that is sized and configured into animplantable shape that conforms to on airway-forming tissue site and iscompatible with normal physiological function after implantation; andstabilizing the implantable shape by incorporating the bioerodiblematerial into the accommodating site. In some of these methodembodiments, changing the initial shape of the resiliently deformablematerial includes absorbing a force sufficient to remodel the airway asthe force is transferred from the device into an implant site afterimplantation of the device. That level of force is further typicallyinsufficient to remodel the airway to an extent that it is unable tomove in a manner that allows substantially normal or acceptablephysiological function of the airway.

As noted above, some aspects of the invention further provide a devicefor alleviating obstruction in an airway, such obstruction typicallyoccurring during sleep. Embodiments of the device include an implantabledevice sized and shaped to conform to an airway-forming tissue site in amanner compatible with normal physiological function of the site, thedevice including a resiliently deformable portion and a bioerodibleportion. In these embodiments, the resiliently deformable portion has apreferred shape that is constrained in a deformed shape by thebioerodible portion, and the device is configured to return toward thepreferred shape of the resiliently deformable portion upon erosion ofthe bioerodible portion. In some embodiments, the preferredconfiguration is adapted to remodel the shape of the airway so as toprovide a more open airway during sleep.

In typical embodiments of the device, the resiliently deformable portionmay include any one or more of a metal or a polymer. In theseembodiments, a resiliently deformable metal may include any one or moreof stainless steel, spring steel, or superelastic nickel-titanium alloy,and a resiliently deformable polymer may include any one or more ofsilicon rubber, polyesters, polyurethanes, or polyolefins. In someembodiments, the bioerodible portion may include any one or more ofpolycaprolactone, polylactic acid, polyglycolic acid, polylactidecoglycolide, polyglactin, poly-L-lactide, polyhydroxalkanoates, starch,cellulose, chitosan, or structural protein.

Some embodiments of the device include a portion adapted to engage thetissue into which it is implanted, and in some of these embodiments, theso-adapted portion includes a site for tissue in-growth, such in-growthserving to keep the device and tissue in close proximity, serving topromote implant site remodeling in a manner that conforms to thechanging shape of the device. Finally, in some embodiments, theimplantable device is configured with sufficient elasticity to allownormal physiological movement around an airway-forming tissue implantsite when the device is implanted in the implant site.

In other embodiments, the adapted portion contains sites for tissue tolink through the implant after implantation forming tissue plugs whichthus form an attachment between the implant and the adjacent tissuewithout a corresponding adhesion of tissue to the implant. This type ofarrangement can produce an implant that can effectively attach to andmove tissue while remaining easily removable from the tissue. The tissueplugs can be formed by linking the implant around an encircled orsurrounded mass of tissue or allowing tissue to heal through the implantthus forming the island of encircled or surrounded tissue. Implants cancontain one or more surrounded masses of tissue allowing attachment tothe adjacent tissue. In some embodiments, a proximal end of the implantis anchored to the patient's mandible and a distal end or ends of theimplant is/are releasably anchored to one or more tissue plugs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides an overview of the healthy human airway anatomy, withparticular attention to the nasopharyngeal, oropharyngeal, andhypopharyngeal regions.

FIG. 2A provides a view of a compromised airway, with an occlusion inthe oropharyngeal region due to posterior slippage of the base of thetongue.

FIG. 2B provides a view of a compromised airway with palate closure.

FIG. 3A depicts an elongate implant component of a revisable OSA implantsystem, the implant having end portions with openings for growth of atissue plug therethrough to secure the end portions in a treatment site.

FIG. 3B is a cut-away view of an end portion of the implant of FIG. 3Ain a tissue site.

FIG. 3C depicts another elongate implant embodiment similar to that ofFIG. 3A.

FIG. 3D depicts another elongate implant embodiment.

FIG. 4 depicts another elongate implant corresponding to aspects of theinvention.

FIG. 5A depicts a second component of a revisable OSA implant system,the second component comprising a cutting tool.

FIG. 5B depicts the cutting tool of FIG. 5A in a method of use.

FIG. 6 depicts an alternative cutting tool similar to that of FIGS.5A-5B.

FIG. 7A depicts another elongate implant corresponding to aspects of theinvention.

FIG. 7B depicts another elongate implant embodiment.

FIG. 7C depicts another elongate implant embodiment.

FIG. 7D depicts another elongate implant embodiment with multipleopenings in multiple planes.

FIG. 7E is a partially cut-away view that depicts an OSA implant with anelastomeric portion that is configured for being releasably maintainedin a tensioned or non-repose condition by a magnesium or magnesium alloybiodissolvable material or element.

FIG. 8A depicts the working end of another embodiment of a cutting toolfor cutting a portion of an implant in situ.

FIG. 8B depicts another embodiment of a cutting tool for cutting animplant in a revision procedure.

FIG. 9 depicts another implant with a medial portion having a surfaceconfigured for low adhesive energy.

FIG. 10 depicts another elongate implant corresponding to aspects of theinvention.

FIG. 11 depicts another implant corresponding to aspects of theinvention including a sacrificial portion that can be sacrificed inresponse to an external stimulus.

FIG. 12 is a cut-away view depicting the implant of FIG. 11 in a tissuesite after actuation of the sacrificial portion of the implant.

FIG. 13A depicts an alternative implant including an electrolyticallysacrificial portion that can be sacrificed in response to a directcurrent.

FIG. 13B is a cut-away view depicting the implant of FIG. 13A in atissue site after actuation of electrolytic connection portion of theimplant.

FIG. 14 depicts an end portion of an alternative revisable implantincluding a cut wire for cutting a tissue plug.

FIG. 15 is a cut-away view depicting the implant of FIG. 14 in a tissuesite in the process of actuating the cut wire.

FIG. 16 depicts an end portion of an alternative revisable implantincluding a cut wire for cutting a plurality of tissue plugs.

FIG. 17 depicts an alternative revisable OSA implant.

FIGS. 18A and 18B illustrate an end portion of the revisable implant ofFIG. 17.

FIG. 19 depicts an alternative revisable OSA implant.

DETAILED DESCRIPTION

A. Anatomy of the Pharynx

FIG. 1 is a sagittal view of the structures that form the pharyngealairway 4; some of these structures can become compromised under variousconditions to the extent that they obstruct or occlude passage of airthrough the airway 4, and thus contribute to obstructive sleep apnea.The pharynx is divided, from superior to inferior, into the nasopharynx1, the oropharynx 2 and the hypopharynx 3. Variations of FIG. 1 areprovided in FIGS. 2A and 2B which depict airway obstruction sites 5 atvarious levels in the pharyngeal airway. FIG. 2A, for example, shows anocclusion 5 at the level of the oropharynx 2, where the base of thetongue 16 and a thickened posterior pharyngeal wall 22 have collapsedagainst each other. FIG. 2B provides a view of a compromised airway withpalate closure. It is also possible for airway obstruction to occur atthe level of the nasopharynx 1, where an elongated and/or floppy softpalate can collapse against a thickened posterior pharyngeal wall.Further, an obstruction can occur at the level of the hypopharynx 3,where both an elongated soft palate and a floppy epiglottis 12 cancollapse against the pharyngeal wall 22.

With reference to FIGS. 1-2B, the nasopharynx 1 is the portion of thepharynx at the level of or above the soft palate 6. In the nasopharynx,a deviated nasal septum or enlarged nasal turbinates may occasionallycontribute to upper airway resistance or blockage. Rarely, a nasal mass,such as a polyp, cyst or tumor may be a source of obstruction. Theoropharynx 2 includes structures from the soft palate 6 to the upperborder of the epiglottis 12 and includes the inferior surface of thehard palate 14, tongue 16, posterior pharyngeal wall 22 and the mandible24. The mandible typically has a bone thickness of about 5 mm to about10 mm anteriorly with similar thicknesses laterally. An obstruction inthe oropharynx 2 may result when the tongue 16 is displaced posteriorlyduring sleep as a consequence of reduced muscle activity during deep ornon-REM sleep. The displaced tongue 16 may push the soft palate 6posteriorly and may seal off the nasopharynx 1 from the oropharynx 2.The tongue 16 may also contact the posterior pharyngeal wall 22, whichcauses further airway obstruction.

The hypopharynx 3 includes the region from the upper border of theepiglottis 12 to the inferior border of the cricoid cartilage. Thehypopharynx 3 further includes the hyoid bone 28, a U-shaped,free-floating bone that does not articulate with any other bone. Thehyoid hone 28 is attached to surrounding structures by various musclesand connective tissues. The hyoid bone 28 lies inferior to the tongue 16and superior to the thyroid cartilage 30. A thyrohyoid membrane and athyrohyoid muscle attach to the inferior border of the hyoid 28 and thesuperior border of the thyroid cartilage 30. The epiglottis 12 isinfero-posterior to the hyoid bone 28 and attaches to the hyoid bone bya median hyoepiglottic ligament. The hyoid boric attaches anteriorly tothe infero-posterior aspect of the mandible 24 by the geniohyoid muscle.Below the hypopharynx 3, the trachea 32 and esophagus 34 are also shown.

B. Revisable OSA Implants

FIG. 3A depicts a first component in an exemplary embodiment of a kit orsystem that provides revisable implants for treating airway disorders orobstructive sleep apnea (OSA). The second component of the exemplary kitis an introducer for insertion into a treatment site as is known in theart and co-pending applications. In FIG. 3A, an elongate device orimplant body 100A has first and second end portions 105A and 105B withthrough-openings 106A and 106B therein. The medial portion 110 of theimplant body 100A extends along axis 111 and comprises a biocompatibleelastomeric material such as a silicone. The mean cross-section of themedial body portion 110 can range from 1 to 10 mm² and can be round,oval, flat, polygonal or other suitable shapes. In some embodiments, theelastic modulus of the medial portion can range from 0.5 to 10 MPA andis configured for implanting in the patient's airway tissue in areleasable, tensioned position, as described in co-pending U.S. patentapplication Ser. No. 11/969,201 which is incorporated herein by thisreference.

Referring to FIGS. 3A and 3B, it can be seen that through-openings 106Aand 106B in the implant body 100A are configured for growth of a tissueplug 112 through the opening to thereby secure the first and second endportions 105A and 105B in a selected tissue, site. The cut-away view ofFIG. 3B schematically illustrates that a tissue plug 112 that growsthrough the opening is thus surrounded or encircled by an encirclingbody portion 115 of the implant. The encircling body portion 115comprises a small cross-section element that can be cut, severed,sacrificed, decoupled, or dissolved to disengage the implant from atissue site 120 as will be described below. The element can be a polymeror other material. In other embodiments described below, the tissue plug112 can be cut or severed to disengage the implant from the tissue site120. In one embodiment, the mean cross-section of the tissue plug 112,and thus the dimension across an opening 106A or 106B, can range fromabout 0.5 mm to 10 mm or more. The openings 106A or 106B can have around shape in plan view or any other plan shape. The end portions 105Aand 105B can have similar or dissimilar configurations, for example animplant configured for treatment of a patient's tongue may have asubstantially larger end portion and opening 106B for the base of thetongue and a smaller end portion near the mandible.

FIG. 3C illustrates another implant body 100B with an end portion 105Bhaving an elongated opening 106B through which tissue will grow to forma tissue plug to secure the end portion in the site. For example, theimplant body 100B of FIG. 3C has an opening 106B with a primary axis 121and larger dimension that extends generally orthogonal to the axis 111of medial portion 110 of the implant body. In use, the greater dimensionof the tissue plug will better resist the retraction forces applied totissue by the elastomeric medial portion 110 of the implant aligned withaxis 111.

FIG. 3D depicts another embodiment 100C of a revisable implant fortreating an airway disorder that is similar to that of FIG. 3C exceptthe end portion 105B has a through-opening 106B with a terminal part 126of encircling portion 115 configured with irregular shaped surfacefeatures 128 that can interface with the tissue plug that grows throughopening 106B. The surface features can comprise undulations, textures,protrusions, bumps and the like that can assist in maintaining the endportion in a fixed position when under the tensioning or retractionforces applied by the medial portion 110 of the implant body 100C. Inthe implant body 100C of FIG. 3D, the end portion 105B also can have anencircling element 115 that includes a proximal portion 130 of a lowermodulus material similar to the modulus of medial portion 110 and theterminal part 126 having a higher modulus to prevent its deformationunder tensioning forces.

FIG. 4 depicts another embodiment 100D of a revisable implant that issimilar to previous embodiments except that at least one end portion105B includes an indent feature 140 in the proximal-facing aspect of theencircling portion 115 wherein the indent feature 140 is adapted todirect and receive a cutting blade or edge 144 (phantom view) of acutting tool for cutting the encircling portion of the implant body toallow its removal from the treatment site. As will be described below(with reference to FIG. 5B), a cutting tool 145 can be advanced alongthe medial portion 110 of the implant to sever the end portion, whichthen will allow the entire implant to be withdrawn from the implantsite. In another aspect of the invention, the indent feature 140 in theencircling portion 115 can direct the cutting edge 144 to a reducedcross section portion 148 that will require limited force to cut thepolymer element with the cutting edge 144.

FIGS. 5A and 5B illustrate a second component of an exemplary kit of arevisable OSA implant system wherein the tool 145 comprises an elongatemember with a distal cutting edge 144. One tool embodiment has apassageway 152 extending therethrough for receiving the elongate implantbody 100D. In using this tool 145, a first end of the implant body wouldbe freed from tissue or cut and then threaded through the passageway152. Thereafter, as depicted in FIG. 5B, the tool 145 can be advanceddistally while holding the proximal end of the implant to cause thecutting edge 144 to cut across the encircling portion 115. In FIG. 5B,it can be understood how the indent feature 140 and reduced crosssection portion 148 (see FIG. 4) direct the cutting edge 144 to easilycut the element to thus release the implant from encircling the tissueplug 112 (cf. FIG. 3B). The tool 145 can be a rigid or semi-rigid membersuch as a hypotube with a sharpened end. The tool also can be adeflectable, articulatable or steerable member as is known in the art.In another embodiment, the tool can be a flexible plastic material witha blade insert to provide the cutting edge 144. Referring to FIGS. 5Band 3B, it can be understood that the cut end is flexible and can bepulled from around the tissue plug to extract the implant from the site120 (see FIG. 3B).

FIG. 6 illustrates another second tool component of a revisable implantsystem wherein the tool 145′ again comprises an elongate member with adistal cutting edge 144. In one embodiment, the tool end includes alongitudinal gap 155 along a side of passageway 152 to thus allow thetool to be inserted over medial portion 110 of an implant body to thenadvance and cut the implant as depicted schematically in FIGS. 5A-5B.The tool end as shown in FIG. 6 can comprise a polymer member withflexible elements 158 on either side of gap 155 to allow gap 155 to flexopen when the device is being inserted over the implant. As depicted,distal cutting edge 144 may comprise a metal blade insert 160 moldedinto a polymer member.

FIGS. 7A-7C illustrate other embodiments of implants 200A, 200B and 200Cthat each has a plurality of through-openings 206 in variousconfigurations. In these embodiments, the ends are flat or planar withthe openings therein. Thus, in use, there will be a plurality of tissueplugs that grow through the openings 206 to secure the implant ends inthe tissue site.

FIG. 7D illustrates another embodiment of implant 200D that has anon-planar end 201 with a plurality of through-openings 202. In oneembodiment, the ends have a plurality of elements 204 that extend indifferent radial angles relative to the axis 111 of the implant witheach such element 204 having one or more openings therein.

FIG. 7E illustrates an implant body 200E with ends 205A and 205B andmedial portion 206 that comprises an axially-stretched and tensionedelastomeric material. The medial portion 206 is releasably andtemporarily maintained in the axially-stretched non-repose condition bya biodissolvable portion, such as of magnesium or magnesium alloy,indicated at 208. In this embodiment, the biodissolvable portion cancomprise a tubular member with a foil-like wall or thin-wall, aplurality of thin-wall tube segments, or one or more windings or braidsof biodissolvable material. The thin-wall material can be perforated asshown in FIG. 7E. The thin-wall biodissolvable material, or thebiodissolvable filament of a winding or braid, can be very fine andadapted to dissolve, erode and/or absorb into the body with selectedtime interval ranging from about 2 weeks to 52 weeks. In anotherembodiment, the biodissolvable portion can be disposed in an interiorportion of the implant body, in a linear or helical configuration.

Embodiments of the invention include methods for opening a collapsed orobstructed airway with devices that can be implanted into varioustissues that form the airway. Embodiments of the devices includeresiliently deformable materials and bioerodible materials. Thedeformable portion of devices, when first formed, is formed into apreferred shape which is then subsequently deformed, and stabilized inthat deformed shape by incorporation or application of bioerodiblematerials to create a device in its implantable form. Once implantedinto a tissue site, and thus exposed to an aqueous environment andsubject to cellular and enzymatic action, the bioerodible portions ofthe device erode, thereby allowing the deformable portion of the deviceto return toward the preferred form. Embodiments of the method, in theirsimplest form, thus include implanting a device, the bioerodible portionof the device bioeroding, the device changing shape as a consequence ofthe bioeroding, and the tissue remodeling in accordance with the forcebeing exerted by the shape changing of the device.

Referring again to FIG. 7E, in operation exemplary device 200E may beimplanted into an airway-interface tissue site, such as a patient'stongue. Device 200E is configured with appropriate characteristics, suchas its dimensions and flexibility, to be compatible with normalphysiological function of the tissue site, such as swallowing andspeech. When first implanted, biodissolvable portions 208 maintainmedial portion 206 in a stretched configuration. As shown, first andsecond openings extend through first and second implant ends 205A and205B, respectively. As the tissue adjacent the implant heals afterdevice 200E is implanted, these openings allow tissue plugs to growthrough them, permitting each of the first and second implant ends tosurround a tissue plug that forms. This allows the ends of implant 200Eto become anchored in the tissue site before portions 208 dissolve andrelease the stored tension between ends 205A and 205B. Oncebiodissolvable portions 208 have dissolved and pre-stretched medialportion 206 applies tension between the tissue plugs, the base of thetongue, for example, is drawn in an anterior direction to open acollapsed or obstructed airway. In some embodiments (not shown), theends of the device may be configured to encircle the tissue plugs uponimplantation, without requiring healing time for the tissue plugs togrow through the openings in the ends of the device. Further details ofsuch devices are provided in U.S. provisional application 61/347,356,and further examples of implantation procedures are provided in U.S.application Ser. Nos. 11/969,201 and 12/937,564.

FIG. 8A depicts the working end 210 of an elongated tool that is adaptedfor cutting an end portion of an implant for its removal, for example animplant of FIGS. 3A-3D, 4, or 7A-7D. The tool functions similar to thatof FIGS. 5A and 6, wherein the tool has a central bore 212 that receivesthe elongate medial portion of an implant body. As can be seen in FIG.8A, the working end 210 includes two concentric hypotubes with a notch214 therein to push over an end portion 115 of implant 100A of FIG. 3A,for example. The physician can counter-rotate the hypotubes from aproximal handle end wherein blade edges 215 and 216 of the working endfunction as a scissors mechanism to cut the implant body. Thereafter,the implant can be easily removed from the treatment site. FIG. 8Billustrates another working end 210′ of a similar cutting tool that hasopposing notches 214 and 214′ that can receive a implant body portionand blade edges 215 and 216 can be rotated or pivoted to cut theimplant.

FIG. 9 illustrates another embodiment of implant 220 that is similar toany previous embodiment except depicting a difference in surfacecharacteristics of the implant. The end or encircling portion 225 mayhave smooth or slightly textured surface features and the medial portion230 may comprise a highly lubricious surface, such as an elastomericmaterial having an ultra-hydrophobic surface 232 to allow for slippageof the tissue against the implant during use. Thus, a method of theinvention comprises implanting a device in airway-interface tissue,securing first and second implant end portions in the tissue bypermitting a tissue growth through at least one opening in an endportion, and allowing an elastomeric portion of the implant to applyretraction forces to alleviate tissue obstruction of the airway whereinan ultahydrophobic surface of the implant prevents tissue adhesion tosaid surface. Ultrahydrophobic surfaces can be provided in abiocompatible polymer, as is known in the art.

In another aspect of the invention, referring to FIG. 9, the elongateimplant body is configured for implanting in an airway-interface and atleast a portion of a body surface has a wetting contact angle greaterthan 70°, to prevent tissue adhesion and to allow tissue slippage. Inother embodiments, at least a portion of a body surface has a wettingcontact angle greater than 85°, or greater than 100°.

In another aspect of the invention, still referring to FIG. 9, theelongate implant body is configured for implanting in anairway-interface and at least a portion of a body surface has anadhesive energy of less than 100 dynes/cm, less than 75 dynes/cm or lessthan 50 dynes/cm.

FIG. 10 illustrates another embodiment of revisable OSA implant 250similar to previous embodiments except the medial portion 252 includes apassageway 254 configured for extending a cutting tool 255 through thepassageway for cutting a distal end portion 258 of the implant. Thepassageway 254 can be accessed by an access opening in the opposing end(not shown) that can be identified by imaging of a marker, visualobservation of a marker, by a left-in place guidewire or other suitablemeans or mechanism. The cutting tool 255 can comprise a scissor member,an extendable blade that is extendable from a blunt-tipped tool, anydistal or proximally-facing blade, and/or any type of thermal energyemitter adapted for cutting the implant end 258.

FIG. 11 illustrates another embodiment of revisable OSA implant 280 thathas a sacrificial portion indicated at 282 that can be severed orsacrificed by an external stimulus. In one embodiment, a medial portion283 of the implant includes electrical contacts or extending leads 284Aand 284B that can be detachably coupled to an electrical source 285. InFIG. 11, the implant body comprises an elastomeric material as describedabove and the sacrificial portion 282 comprises a conductively dopedpolymer portion that acts as a fuse when subject to a very short burstof high voltage RF current. Opposing sides or aspects of the sacrificialportion 282 are coupled to electrical leads 288A and 288B that areembedded or molded into the implant. The use of such doped polymers fora fuse-effect for detachment of endovascular medical implants isdisclosed in U.S. Pat. No. 6,458,127 to Truckai et al and issued Oct. 1,2002, which is incorporated herein by reference. Similar doped polymerscan be used in the revisable OSA implant of FIG. 11.

FIG. 12 illustrates a method of using the OSA implant 280 of FIG. 11,and more particularly for revising the treatment. FIG. 12 depicts thatan RF current from source 285 has been delivered to melt, sever andsacrifice portion 282 of the implant thus allowing extraction of theimplant from around the tissue plug.

FIGS. 13A and 13B illustrate another embodiment of revisable OSA implant290 that has a sacrificial portion indicated at 282 in a medial portionof the implant that can be actuated and sacrificed by the externalstimulus which then leaves the encircling portion 115 of the implant inplace. The left-in-place portion of the implant can be used as an anchorfor subsequent implants. In one embodiment as in FIGS. 13A-13B, thesacrificial portion 282 can comprise an electrolytic wire that can besacrificed over a short time interval by direct current as is known inthe art. Such electrolytic wire for detachment of embolic coil implantsare known in the field of aneurysm implants and treatments.

While FIGS. 11-13B show OSA implants with two forms of sacrificialportions, it should be appreciated that similar implants can havesacrificial portions that are cut, severed or sacrificed by any externalstimulus such as RF current, DC current, light energy, inductive heatingetc. and may fall within the scope of the invention.

FIGS. 14 and 15 illustrate another embodiment of revisable OSA implant300 that again includes at least one end with an encircling portionindicated at 315 that encircles or surrounds a tissue plug 316 thatgrows through an opening 320. In one embodiment, the implant carries acut wire 322 that extends in a loop with first and second wire ends 324Aand 324B extending through one or more passageways in the implant. Thecut wire 322 can be embedded in the surface of the implant surroundingthe opening 320. As can be seen in FIG. 15, the looped cut wire 322 canbe pulled proximally to cut the tissue plug 316 which then will free theimplant from its attachment. In FIG. 14, it can be seen that the cutwire ends 324A and 324B can have a serpentine configuration in themedial portion of the implant so as to not interfere with the tensioningand relaxation of the elastomeric medial implant portion during its use.When the cut wire is accessed and pulled relative to the implant 300,the tissue plug 316 can be cut. It should be appreciated that othertools (not shown) may be used to stabilize the implant when actuatingthe cut wire as in FIG. 15. The cut wire 322 can be any form of finewire, or abrasive wire or a resistively heated wire coupled to anelectrical source (not shown).

FIG. 16 depicts another revisable USA implant 300′ that is similar tothat of FIGS. 14-15 with the cut wire 322′ configured to cut a pluralityof tissue plugs 316 that have grown through openings 320 within anencircling end portion of the implant body.

FIG. 17 depicts another OSA implant 400 that is adapted for revision asprevious implants and systems wherein the elongate device or implantbody has first and second end portions 405A and 405B withthrough-openings 406A and 406B therein. The medial portion 411 ofimplant body 400 extends about an axis and comprises a biocompatibleelastomeric material such as a silicone. In this embodiment, the medialportion comprises first and second extending portions 415A and 415Bwherein one such portion can be nested in a passageway 416 of the otherportion and then form proximal and distal loops or encircling endportions that define openings 406A and 406B for receiving tissue plugstherein. As can be understood from FIGS. 17 and 18A, both the extendingportions 415A and 415B comprise an elastomeric material and thus combineto provide the desired retraction forces of the OSA implant.

Referring to FIGS. 18A and 18B it can be seen that if the secondextending portion 415B is cut in a medial or proximal aspect of theimplant, or if both the first and second extending portions 415A and415B are cut in a proximal or medial aspect, then a proximal aspect ofthe first or outer extending portion 415A can be pulled in the proximaldirection and the cut second extending portion 415B then will snake outof the path around the tissue plug 422. Thus, the implant can be cut ina proximal or medial aspect and can be withdrawn from the treatment sitefrom a remote access location.

FIG. 19 depicts another OSA implant 450 that is adapted for a revisionprocedure and comprises an elongate implant body with first and secondend portions 455A and 455B with through-openings 456A and 456B therein.This embodiment is similar to that of FIG. 17 in that medial portion 458includes extending portions 460A and 460B comprising an elastomericmaterial that combine to provide the desired retraction forces of theOSA implant. The extending portions 460A and 460B are carried in a thinelastomeric sleeve 464 that has tear-away portions 465 about its ends toprevent tissue ingrowth into the passageway in the sleeve. It can beunderstood that by cutting the medial portion of the implant, and thenpulling on an end of an extending portion 460A or 460B will cause theother free end of the implant to snake around the tissue plug similar tothe method depicted in FIG. 18B. Both ends of the implant can be removedfrom the treatment site by this method.

The embodiments of implants shown in the figures above can be sized andshaped to conform to a treatment site in a patient's tongue, palate orother site in airway-interface tissue and to reside in an orientationand in a manner compatible with normal physiological function of thesite. The overall dimensions may vary according to the full extent thathuman subjects vary in their anatomical dimensions, and thus thedimensions provided here are only an approximation for the purpose ofillustration, and are not meant to be limiting. Any embodiment in itselongated state may typically be in the range of about 2 cm to about 10cm in length in a releasably extended state, and the implant in acontracted state may be in the range of about 1 cm to about 6 cm inlength.

Unless defined otherwise, all technical terms used herein have the samemeanings as commonly understood by one of ordinary skill in the art towhich this invention belongs. Specific methods, devices, and materialsare described in this application, but any methods and materials similaror equivalent to those described herein can be used in the practice ofthe present invention. While embodiments of the inventive device andmethod have been described in some detail and by way of exemplaryillustrations, such illustration is for purposes of clarity ofunderstanding only, and is not intended to be limiting.

Various terms have been used in the description to convey anunderstanding of the invention; it will be understood that the meaningof these various terms extends to common linguistic or grammaticalvariations or forms thereof. It will also be understood that whenterminology referring to devices or equipment has used trade names,brand names, or common names, that these names are provided ascontemporary examples, and the invention is not limited by such literalscope. Terminology that is introduced at a later date that may bereasonably understood as a derivative of a contemporary term ordesignating of a subset of objects embraced by a contemporary term willbe understood as having been described by the now contemporaryterminology.

While some theoretical considerations have been advanced in furtheranceof providing an understanding of the invention the claims to theinvention are not bound by such theory. Described herein are ways thatembodiments of the invention may engage the anatomy and physiology ofthe airway, generally by opening the airway during sleep; thetheoretical consideration being that by such opening of the airway, theimplanted device embodiments alleviate the occurrence of apneic events.Moreover; any one or more features of any embodiment of the inventioncan be combined with any one or more other features of any otherembodiment of the invention, without departing from the scope of theinvention. Further, it should be understood that while these inventivemethods and devices have been described as providing therapeutic benefitto the airway by way of intervention in tissue lining the airway, suchdevices and embodiments may have therapeutic application in other siteswithin the body, particularly luminal sites. Still further, it should beunderstood that the invention is not limited to the embodiments thathave been set forth for purposes of exemplification, but is to bedefined only by a fair reading of claims that are appended to the patentapplication, including the full range of equivalency to which eachelement thereof is entitled.

What is claimed is:
 1. A method for treating an airway disorder comprising: providing an implant body having first and second end portions configured to surround first and second spaced apart tissue plugs, respectively; implanting the body in an airway-interface tissue; applying tension between the tissue plugs with the implant body to draw the tissue plugs closer together to thereby alleviate tissue obstruction of the airway; and cutting the first or second end portions to disengage the implant body from the airway-interface tissue.
 2. The method of claim 1 where the implanting includes releasably maintaining the implant body in a tensioned configuration for a selected time interval.
 3. The method of claim 2 wherein a portion of the implant body is releasably maintained in the tensioned configuration by a bioerodible or biodissolvable material.
 4. The method of claim 3 wherein the bioerodible or biodissolvable material is carried about an exterior of the implant body.
 5. The method of claim 3 wherein the bioerodible or biodissolvable material is carried within an interior portion of the implant body.
 6. The method of claim 1 wherein the applying tension includes releasing the implant body from a tensioned configuration to move toward a non-tensioned configuration.
 7. The method of claim 6 wherein the releasing comprises allowing the bioerodible or biodissolvable material to erode or dissolve.
 8. A system for revisably treating an airway disorder, comprising: an implant body configured to conform to an airway-interface tissue site in a manner compatible with normal physiological function of the site, the implant body having a medial portion, first and second openings extending through first and second implant ends, respectively, for permitting each of the first and second implant ends to surround a tissue plug wherein the first and second implant openings are each formed by a flexible loop at either the first or the second implant end, said flexible loops adapted to surround the tissue plugs and to disengage the implant body from the airway-interface tissue site by releasing the surrounded tissue plugs after the flexible loops have been cut, wherein at least a portion of one of the flexible loops has a higher modulus than that of the medial portion to prevent deformation of the flexible loop under tensioning forces, wherein at least one of the flexible loops comprises a proximal portion of a lower modulus material similar to a modulus of the medial portion of the implant body, and a terminal part having a higher modulus to prevent its deformation under tensioning forces.
 9. The method of claim 1, wherein the first and second end portions of the implant body each comprise a loop, and wherein at least a portion of one of the loops has a higher modulus than that of a medial portion of the implant body to prevent deformation of the loop under tensioning forces.
 10. The method of claim 1 where the first and second tissue plugs grow through the first and second end portions of the implant body, respectively, after the body is implanted.
 11. The method of claim 1 where the first and second end portions are provided in the implant body in a releasably tensioned configuration, the releasably tensioned configuration being releasably maintained by a bioerodible or biodissolvable material carried by a medial portion of the implant body.
 12. The method of claim 1 further including cutting said tissue plugs and extracting the implant from the tissue to revise treating.
 13. The method of claim 1 further including extracting the implant body from the airway-interface tissue to revise treating.
 14. A system for revisably treating an airway disorder, comprising: an implant body configured to conform to an airway-interface tissue site in a manner compatible with normal physiological function of the site, the implant body having a medial portion, first and second openings extending through first and second implant ends, respectively, for permitting each of the first and second implant ends to surround a tissue plug wherein the first and second implant openings are each formed by a flexible loop at either the first or the second implant end, said flexible loops adapted to surround the tissue plugs and to disengage the implant body from the airway-interface tissue site by releasing the surrounded tissue plugs after the flexible loops have been cut, wherein at least a portion of one of the flexible loops has a higher modulus than that of the medial portion to prevent deformation of the flexible loop under tensioning forces.
 15. The system of claim 14 further comprising a cutting element configured for removal of the implant body from the site.
 16. The system of claim 15 wherein the cutting element comprises at least one of a pivotable blade edge, a rotatable sleeve with a blade edge, an axially translatable blade edge, and a cut wire.
 17. The system of claim 14 wherein the medial portion is configured for implantation in the airway-interface tissue site in a non-repose condition.
 18. The system of claim 17 wherein the medial portion is configured to be releasably maintained in the non-repose condition by a bioerodible or biodissolvable material carried by said medial portion.
 19. The system of claim 14 wherein the first and second openings of the first and second implant ends are configured to allow the tissue plugs to grow therethrough after the implant body has been implanted in the airway-interface tissue site.
 20. The system of claim 14 wherein the medial portion comprises an elastomeric material.
 21. The system of claim 14, wherein the loops comprise an elastomeric material.
 22. The method of claim 9, wherein the least one of the loops comprise a proximal portion of a lower modulus material similar to a modulus of the medial portion of the implant body, and a terminal part having a higher modulus to prevent its deformation under tensioning forces. 